There exists a need for reliable, low cost analytical devices that allow for the rapid separation and detection of micro quantities of cellular tissue, genetic material, organic molecules, sequencing, etc. for use in research as well as in the diagnosis of disease(s) or the existence of certain predetermined conditions. DNA analysis is an effective approach for the detection and identification of viruses, bacteria, and other microbes and is essential to the identification of genetic disorders. The ability to detect DNA with a high level of specificity entails high resolution separation of RNA or DNA fragments, appropriate labeling chemistry for such fragments and the adaptation of high sensitivity sensors that are specific for the labeling chemistry employed. DNA probe technology is now an established tool of the molecular biologist for revealing the presence of diagnostically significant cells, whether they be diseased cells from the subject or infectious micro organisms.
Recently, DNA analysis devices have experienced a miniaturization trend similar to that experienced in the electronics industry with the advent of integrated circuits. Many of the same principles that have led to smaller and smaller micro processor devices have shrunk the size of a chemistry lab to a device no larger than the size of a dime. The techniques are all aimed at producing a device having different, discreet areas that are sensitive to different genetic sequences. These areas, or probes, are formed using a number of techniques, including photo patterning methods, such as photolithography, which is a direct descendant from techniques used in the manufacture of micro processor chips; micro machining, where tiny channels are machined into a chip to hold various test media; and other methods of precisely depositing test media upon chips in a precisely defined pattern.
While these methods do allow for the manufacture of acceptable biosensor chips, they do have a number of drawbacks. One significant drawback is the sophistication and expense of photo patterning, micro machining and micro-media deposition devices that are capable of producing biosensor chips including hundreds or thousands of individual probes. Additionally, the use of these prior art methods requires extreme precision in the deposition of test materials since their deposition involves microscopic quantities and positions. This also leads to significant quality control issues, since a single biosensor chip can have literally thousands of separate probes, each of which requires testing or verification.
Due to these drawbacks and limitations, biosensor chips are expensive to manufacture and although they provide significant improvements in the state of the art, they have not yet experienced wide scale implementation. In addition, the technology is too expensive for implementation with respect to low cost diagnostic tests.
Accordingly, there is a need for an improved biosensor chip or device and method of manufacturing the same, which can result in inexpensive biosensor devices that can be manufactured using cost effective machinery. Additionally, there is a need for a biosensor device that can be highly reliable due to improved quality assurance procedures performed during the manufacture thereof. Finally, a biosensor device is needed that can utilize the same manufacturing methods for a wide variety of analysis protocols including both sophisticated and simple analytical procedures.